Threading of sewing machine needles



M. N. BENNISON THREADING OF SEWING MACHINE NEEDLES Sept. 10, 1968 3 Sheets-Sheet 1 Filed March 18, 1966 m- 10, 1968 M. N. BENNISON 3,400,678

THREADING OF SEWING MACHINE NEEDLES Filed March 18, 1966 3 5 Sheets-Sheet 2 Sept. 10, 1968 MQN. BENNISON 3,400,678

THBEAD'ING OF SEWING MACHINE NEEDLES Filed March 18, 1966 5 Sheets-Sheet 3 United States Patent 6 Claims. (Cl. 112-225) ABSTRACT OF THE DISCLOSURE A mechanical needle threader for threading the needle of a sewing machine in any position in which the needle may be stopped with the needle eye clear of the presser foot, and so designed that the needle threader can be built as an independent attachment aflixable to the head of a existing conventional sewing machine, comprising a spring-loaded threader element carrier movably linked to a guide member lowerable from an upper position down the side of the needle into a position in which said guide member is intercepted by a part associated with the needle bar, by the application of downward thrust to the threader element carrier first to lower the threader element carrier bodily together with the guide member into said lower position and then to displace the threader element carrier in relation to the guide member to advance the threader element through the needle eye.

This invention relates to the threading of sewing machine needles.

It is well known that time is wasted in threading sewing machine needles and this is particularly so with industrial machines. Hitherto thread has been threaded through the needle manually by the operator and this a a quick operation only by having good eyesight and a lot of practice on the part of the person.

For many years it has been known that a mechanical form of threader would be an asset but the main difficulty has been the .fact that the needle bar carrying the needle does not always stop at the same height in relation to the machine work plate. Moreover, a mechanical form of threader must be sufiiciently robust to withstand any rough treatment in factories and the threader should always be accurately registered automatically with the needle eye.

The main object of the present invention is to provide an improved method of, and means for, threading sewing machine needles.

Accordingly there is provided a method of threading a needle of .a sewing machine, consisting in ensuring a threader element is initially positioned so that its path of operative movement is first registered with the needle eye irrespective of the arrested position of the eye, and then causing such element to pass through the eye, a thread engaged with the end of said element, and then allowing such threader to be withdrawn for the thread to be drawn through the eye.

The method may include giving bodily movement to a threader element into association with the machine needle bar so that the element registers itself vertically to be movable through the needle eye. The method includes causing a threader element to have bodily movement for its operative path to be registered vertically and then laterally in relation to the needle eye, and then to follow an arcuate path to pass through said eye.

The present invention includes a threading device which can readily be mounted on a sewing machine and when operated a threader element will be first positioned 3,460,678 Patented Sept. 10, 1968 vertically and then laterally in relation to a sewing ma chine needle eye, for the threader element to always be automatically registered for passage through the eye, and then the threader element given arcuate movement forwardly and back to receive and then draw thread through the needle.

The invention will now be more particularly described with reference to the accompanying drawings, in which:

FIG. 1 is a perspective front and side view of an improved needle threader device mounted on a sewing machine;

FIG. 2 is a rear elevation of the device with the operating lever broken away for illustrative purposes;

FIG. 3 is a side view of the device in position;

FIG. 4 is an opposite side elevation to FIG. 3 of the the device alone;

FIG. 5 is an enlarged front view of the transverse and vertical locator means in a rest position;

FIG. 6 is :a front view of a modified form of threader device on a sewing machine; and

FIG. 7 is a side view of FIG. 6-.

In a particular embodiment of this invention, a needle threading device includes a mount in the form of a T- shaped bracket 1 which can be secured to the sewing machine head or other part of the machine structure. Conveniently, this bracket has a hole {for it to be fitted up on to the bush 2 through which the presser foot bar 3 passes. A locking screw 4 (or other means) is provided for securing the bracket. This bracket provides a pendant guide bar 5 on which a guide member in the form of a slide block 6 is mounted and this block provides a horizontal pivot pin 7 for a carrier lever 8 which has a horizontal bar 9 extending at right angles towards the vertical reciprocating needle bar 10 of the machine 11 to lie on one side thereof and form a carrier for a threader element 12. The lever 8 has a return spring 13. The slide block 6 is prevented from rotating such as by the sectional shape of its guide bar and/or by .a flat face of the block sliding against a pendant guide plate 14 which forms part of the bracket 1. The threader 12, which is detachably mounted for replacement, comprises a curved thin wire with a hooked or barbed tip 15. Conveniently, the tail end of the wire is coiled to fit on to the bar 9 which is located at 'its other end in a socket 16 extending from the lever 8. The socket can include a spring to provide a linear resilient loading for the bar 9 and thus a slight lateral floating action for the wire 12.

A second carrier lever 17 is pivotally mounted on the slide block pivot pin 7 with the carrier lever 8. This second carrier lever has a carrier bar 18 extending at right angles thereto parallel with the first carrier bar 9 for the threader element, and these two bars are joined closely together by a coiled spning 19'. The two bars have their axes at the same radius from the slide block pivot pin 7 on which the levers 8 and 17 are mounted. The second bar 18 has a pendant location member 20 at its end for locating the threader 12 laterally in relation to a needle eye.

The member 20 has a longitudinal arcuate slot 21 through which the end of the bar 9 projects and the wire tip 15 normally lies in a hole 22 formed in the end of the member from the end of the slot 21 to the member end face 23. A location groove 24 is formed in said face, the hole emerges in the groove, and such groove serves to locate the member 20 and the machine needle (which it receives) in correct lateral alignment when the member swings down. To facilitate the wire being positioned, a small groove 25 is formed in the outer face of member 20 so that as the bar 9 is pushed into its socket the wire 12 flexes and its tip slips into the hole 22.

An operating lever 26 is pivoted on the fixed pivot pin 27 provided on the mounting bracket plate 14. This lever has a straight linear slot 28 (it could be forked) inclined upwardly at rest and a roller 29 projects into the slot from the first carrier lever 8. This lever 26 has an Operating arm 30, a bent rod, which extends under the machine head to a position convenient for a machine operator to depress the end finger element 31. The lever 26 is held raised by the spring 32 secured to the anchor rod 33 carried by the bracket 1.

The aforesaid slide block 6 is also furnished with a horizontally positioned fixed location arm 34 which extends towards the needle bar for its free end to rest down upon the needle clamp 35 when the aforesaid operating arm is depressed. In some machines the said location arm 34 will be adapted to engage the screw which secures the needle 36 in the bar, or a collar or other projection on the bar. This location arm is for initially positioning the threader 12 vertically in relation to the needle eye.

Sewing machine needles 36 can vary in length or at least in the positioning of the eye, and thus it is policy to provide some setting means which will allow for variation in the position of the needle eye. It will be understood that needles are changed in machines and this invention takes care of such a change taking place and any variation in the length of the needle and the position of the needle eye. Conveniently, the location arm 34 of the needle threading device is furnished at its outer end with adjustable means to engage the needle clamp 35, or other projection, on the needle bar 10 of the sewing machine 11. For example, the adjustable means comprises a set screw 37, with or without a lock nut. Alternatively, the end of the location arm may be adjustable in relation to the remainder of the arm or the whole arm may be adjustable on the slide block 6 which carries it.

The aforesaid device is constructed so that the mounting bracket and its closely adjacent parts are on the far side of the machine away from the machine operator so as not to be in the way during normal sewing operations. Thus only the needle threader and the vertical and lateral location means together with part of the operating arm are adjacent but raised clear of the sewing machine needle.

In operation, when the operating arm 30 is depressed it gives a pivotal downward movement to the operating lever 26 which first causes the slide block 6 to descend. Due to this block providing a pivot pin 7 for the carrier lever 8 of the threader 12 and the carrier lever 17 of the lateral locator 20, these also descend until the screw 37 of the aforesaid location arm 34 engages the needle bar projection (clamp, screw or other means). When this occurs, continued depression of the operating arm 30 causes the operating lever 26 to pivot further and this causes the needle threader lever 8 and the lateral location lever 17 to swing down about the pivot 7 on the slide block 6. Thus the device will have first been located vertically in relation to the needle eye and the pivotal movement of the carrier levers causes the lateral locator 20 to swing into engagement with the machine needle 36 which automatically registers the tip of the needle threader 12 laterally in relation to the needle eye. The threader 12 and locator 20 swing down together due to their two carrier bars 9 and 18 being anchored together by the spring 19. When registered, the threader 12 automatically passes through the end of the locator and the needle eye for sewing machine thread 37a to be engaged with the tip of the threader 12. This action occurs because the locator 20 is stationary bearing against the needle and the threader carrier bar 9 can move away from the locator carrier bar 18 due to the spring 19. The operating arm 30 can then be released and due to the spring loading 13 and 32 all the parts will return to a rest position thus causing the threader 12 to draw the thread 37a through the eye of the needle 36.

In a modified embodiment of this invention, as illustrated in FIGS. 6 and 7, a needle threading device includes a mounting bracket 1' which can be secured to a sewing machine head or other part of the machine structure. This bracket provides a pivot pin 27 for a main carrier arm in the form of a guide lever 38 which extends towards the needle bar 10, to lie on one side thereof, and is furnished with a pivot pin 39 on which a pivoted carrier lever 40 is mounted. Guide lever 38 is biassed upwardly to its rest position by a tension spring 50 the ends of which are secured to mounting bracket 1' and lever 39. Carrier lever 40 has a threader element 12 mounted on a horizontal bar 41 at its free end. The forward end of guide lever 38 is provided with a laterally extending rigid extension arm 38a on which an associated location arm 42 is adjustably mounted at 4211, and this second arm 42 passes on the other side of the needle bar to engage a part 43 projecting from the needle bar. To ensure correct location the bottom edge 44 of the location arm 42 is a knife edge to enter a V-groove 45 in the needle bar part 43. This assembly of two arms is spring loaded to a raised position by spring and the pivoted carrier lever 40 is independently spring loaded at 46 to a raised, i.e., withdrawn position. An operating lever 47 is mounted on the pivot pin 27 for the aforesaid two arms and its forwardly projecting free end is provided with a roller 48 to engage a cam face 49 on the rear edge of the threader carrier lever 40.

With the above construction, finger pressure on the operating lever 47 will depress the whole assembly bodily about the main pivot of the mounting bracket until the location arm 42 engages the needle bar part 43 and when this occurs the arcuate operating path of the threader element will have automatically been registered vertically and laterally with the eye of the needle. Continued down pressure will then cause the carrier lever 40 to swing about its pivot 39 and the threader will pass through the eye of the needle. Sewing thread can then be engaged with the element whereupon release of the finger pressure will cause the threader to withdraw with the thread and the whole device will be returned to its rest position. The thread need not be disengaged from the threader which can be adjustably mounted for setting and renewal purposes. The threader may be of some other form including a very springy thin loop formation.

Although it is preferred to give arcuate movement to the threader about a pivot aligned with the needle bar, such threader can be mounted on a plunger or other means to have straight line motion. Here again the threader and its carrier will be mounted to be first registered with the needle eye to ensure correct operation.

What I claim is:

1. The combination with a conventional sewing machine having a presser foot bar and a vertically reciprocating needle bar provided with a clamp securing a needle to the needle bar, of a mechanical device for threading the needle, said needle threading device including a mount securing the device to the head of the sewing machine in the vicinity of the needle, a guide member supported on said mount for displacement between an upper rest position and a lower stop position for needle threading, said stop position being established by contact between a part carried by said guide member and a part carried by said needle bar, spring means cooperative with and biasing said guide member to said upper rest position, a carrier lever member having a threader element thereon, pivot means connecting said carrier lever member to said guide member for an initial downward movement of said carrier lever member and said guide member together until said guide member reaches said stop position and for subsequent pivotal movement of said carrier lever member on said guide member about said pivot means, and manually operated actuating means operatably connected to said carrier lever member for effecting said initial downward movement of said guide member and carrier lever member together from said upper rest position to said lower stop position whereby said threader element on said carrier lever member is brought into a position for proper alignment with the eye in the needle, and for thereafter actuating said carrier lever member pivotally on said stopped guide member thereby to advance said needle threader element through the needle eye.

2. The combination as defined in claim 1 and wherein said mount securing said needle threading device to the head of the sewing machine includes means for attaching the mount at the underside of the head to the bushing through which the presser foot bar descends from the head.

3. The combination as defined in claim 1 and which includes means on said mount supporting said guide member for displacement in a vertical linear path parallel to the needle, wherein said carrier lever member for said threader element is constituted by a first lever pivotally attached to said guide member for deflection in a plane parallel to the plane containing the needle and needle eye axis, wherein said first lever includes a lateral extension to which said needle threader element is afiixed for swinging movement in said plane containing the needle and needle eye axis, and wherein said manually operated actuating means is constituted by a second lever which includes a cam slot engaged with cam slot follower means on said first lever, initial movement of said second lever serving to actuate said first lever and said guide member together from said upper rest position of said guide member to said lower stop position, and further movement of said second lever serving to eflFect further pivotal movement of said first lever thereby to advance said threader element through the needle eye.

4. The combination as defined in claim 3 and which further includes means for guiding said swinging movement of said lateral extension on said first lever and hence also said threader element, said guide means including a third lever also pivotally attached to said guide member parallel with said first lever and having the same pivotal axis of said first lever, spring means interconnecting said first and third levers, said third lever being actuated by said interconnecting spring means and also including a lateral extension terminating in a locating member having an arcuate guide slot in which said lateral extension of said first lever and the entire length of said threader element are received, the leading end face of said locating member at one end of said guide slot including a groove to receive the stem portion of the needle so as to be stopped thereby as said third lever is actuated by said first lever, and a passageway extending from one end of said guide slot to said groove in alignment with the needle eye for passing through the leading end of said threader element into the needle eye as movement of said first lever is continued after said third lever is stopped by contact between said groove in said locating member and the stem portion of the needle.

5. The combination as defined in claim 1 wherein said guide member is constituted by a guide lever pivotally secured at one end thereof to said mount and which is swingable in a plane parallel to the plane containing the needle and needle eye axis from said upper rest position to said lower stopped position, wherein said threader element carrier lever member is pivotally secured to the other end of said guide lever, and wherein said manually operated actuating means is constituted by a third lever pivotally secured at one end thereof to said mount and including a cam roller thereon engaging a cam surface on said threader element carrier lever, initial movement of said third lever serving to actuate said threader element carrier lever and guide lever together from said upper rest position of said guide lever to said lower stopped position, and continued movement of said third lever thereafter serving to effect pivotal movement of said threader element carrier lever relative ot said stopped guide lever thereby to advance said threader element through the needle eye.

6. The combination as defined in claim 5 wherein the lower stopped position for said guide lever is established by a laterally extending arm thereon and including a part engageable with a part carried by said needle bar, the contacting surfaces of said arm part and needle bar part having interengaging geometries in the form of a knife edge and V-slot disposed to force said guide lever into correct transverse alignment with respect to the needle to ensure registry of said threader element with the needle eye transversely and lengthwise of the needle.

References Cited UNITED STATES PATENTS 2,544,577 3/1951 Weber 112-225 RICHARD J. SCANLAN, JR., Primary Examiner. 

